The electrical power industry has a recognized need to periodically inspect both the right-of-way for electric transmission lines and the tower structures and related equipment supporting the transmission lines along the right-of-way.
Currently accepted systems utilize walking/driving patrols combined with climbing the towers or the use of bucket trucks to inspect the towers and the equipment on the towers. Another accepted method of inspection is the use of rotary wing aircraft (helicopters) to fly by and hover at the towers to inspect the towers and equipment. Another possible method uses fixed wing aircraft and expensive custom designed electronic equipment to perform this service from high altitudes, e.g., heights of 1,500 to 6,000 above the towers and have used expensive cameras, custom designed electronic equipment to control the cameras, and sophisticated stabilization equipment to support the cameras. All of these accepted methods contemplate acquiring a photographic record of the tower and tower supported equipment for inspection, and archiving in a database, e.g., an asset management database.
The basic objective of inspecting the power lines, the right-of-way and the towers and tower supported equipment is to detect problems in the right-of-way and defects in the equipment supported on the towers and used in conjunction with the transmission power lines, e.g. insulators, hardware and the like, and the lines themselves at the tower structure.
The problems with these accepted methods is quality of the images, the data acquired, and the cost attendant all of the methods and particularly those that provide the more reliable data. Cost is usually measured in cost per mile of line inspection. High altitude and fixed wing systems are not feasible both from the standpoint of cost and the quality of the images obtained, at least in the acquisition of images of the tower structure per se and the tower supported equipment. The other alternatives in part predated the high altitude systems and were and continue to be accepted as the best currently available and workable alternatives to high altitude systems but have their own shortcomings. More particularly, walk/drive and climb have the potential to provide the most reliable and useable data but has the highest cost. Helicopter inspection is more cost effective than walk/drive and climb but still involves a relatively high cost. Helicopter inspection relies on multiple member crews, flying between and hovering at the towers to visually inspect the structure and equipment and obtaining a film record if a defect is detected. Helicopter inspection offers a better cost structure than walk/drive and climb but involves substantial time in acquiring the images and sacrifices some of the quality of results that can be obtained with walk/drive and climb.
One of the objectives of this invention is to provide reliable and accurate images of the tower structures of an electric transmission line and related equipment supported on those tower structures which can be used to detect defects in the tower structure itself, the equipment supported on the tower structure, as well as the transmission lines as they are connected at the towers, and to do so in a cost effective manner.
Another objective of this invention is to provide a reliable and accurate record of the right-of-way of an electric transmission line, and to do so in a cost-effective manner.
More broadly, it is among the objectives of this invention to provide aerial images of ground structures, apparatus, roadways and the like in an accurate, reliable and cost-effective manner.